WebDAV Mount vs Network Drive: The Latency Test No One Talks About

A recent review of WebDAV mounts versus network drive mappings for NAS file systems reveals that WebDAV mounts are only slightly slower than network drives, yet the difference is often negligible for daily use. To test this claim, the author conducted a 90-day side-by-side comparison of WebDAV mounts and network drive mappings on a Synology DS220+ NAS, using 10,000 mixed files totaling 87GB. The test measured latency for read and write operations, as well as app launch times.

Read latency tests showed that WebDAV mounts were consistently 30-50% slower than network drives on initial file opens. This is due to WebDAV over HTTPS adding extra TLS overhead and per-request headers that SMB does not require. However, once a file is open, the read stream is similar, and the performance difference becomes minimal.

Repeated reads of the same files also showed that the performance gap was primarily due to the initial handshake and not the actual data transfer. After the file is cached in the OS page cache, the second open is nearly as fast as with SMB.

Write latency tests revealed that WebDAV writes were 10-15% slower than SMB writes. This is because WebDAV needs to confirm the upload and update server-side metadata, while SMB handles this implicitly. App launch times were also tested, with WebDAV mounts showing a small but noticeable delay compared to network drives. The author found that most applications, including VS Code, Photoshop, and Premiere, experienced only a 3-4 second difference in cold start times.

One notable failure mode was observed when network connectivity was lost for a few seconds. In this scenario, WebDAV mounts failed to reconnect automatically, causing the app to display "file not found" errors. In contrast, SMB mounts automatically retry and recover from temporary network disruptions. This failure mode can be frustrating for users with unstable networks, such as those using Wi-Fi or VPNs.

The scorecard categorizes WebDAV mounts as excellent for document editing, photo browsing, and code editing, while they are good for photo playback but acceptable for video editing. However, mass file moves are poor, and unstable networks make WebDAV mounts impractical. The review recommends WebDAV mounts for users editing documents, photos, or code, as well as those with stable gigabit connections, cross-platform mounts, or those accessing their NAS remotely.

The ScsDriver software costs $5.5 per lifetime, making it a reasonable investment for these use cases. For video editors or users with flaky networks, the author suggests sticking with SMB mounts.

In conclusion, WebDAV mounts are a viable default solution for 80% of users who primarily work with documents, photos, or code. For the remaining 20% of users who require faster performance for video editing or massive file transfers, the author recommends trying WebDAV mounts on a 30-day trial basis to determine if the performance difference justifies the cost.